使用方法
首先要生成一个可用的套接字描述符,TCP或UDP的都可以,为方便一般使用UDP套接字描述符
然后调用ioctl函数获取所有网络接口列表(struct ifconf), 网卡越多列表数目越多
再次调用ioctl函数从一个个网络接口中获取子项(struct ifreq)进行输出
每获取一个子项(属性)都要调用一次ioctl函数, 因为在struct ifreq中使用了union结构, 一次只能正确返回一个属性
接口结构
以下结构摘自net/if.h头文件中,头文件中定义了很多宏来简化结构成员的访问
struct ifreq {
# define IFHWADDRLEN 6
# define IFNAMSIZ IF_NAMESIZE
union {
char ifrn_name[IFNAMSIZ]; /* Interface name, e.g. "en0". */
} ifr_ifrn;
union {
struct sockaddr ifru_addr;
struct sockaddr ifru_dstaddr;
struct sockaddr ifru_broadaddr;
struct sockaddr ifru_netmask;
struct sockaddr ifru_hwaddr;
short int ifru_flags;
int ifru_ivalue;
int ifru_mtu;
struct ifmap ifru_map;
char ifru_slave[IFNAMSIZ]; /* Just fits the size */
char ifru_newname[IFNAMSIZ];
__caddr_t ifru_data;
} ifr_ifru;
};
# define ifr_name ifr_ifrn.ifrn_name /* interface name */
# define ifr_hwaddr ifr_ifru.ifru_hwaddr /* MAC address */
# define ifr_addr ifr_ifru.ifru_addr /* address */
# define ifr_dstaddr ifr_ifru.ifru_dstaddr /* other end of p-p lnk */
# define ifr_broadaddr ifr_ifru.ifru_broadaddr /* broadcast address */
# define ifr_netmask ifr_ifru.ifru_netmask /* interface net mask */
# define ifr_flags ifr_ifru.ifru_flags /* flags */
# define ifr_metric ifr_ifru.ifru_ivalue /* metric */
# define ifr_mtu ifr_ifru.ifru_mtu /* mtu */
# define ifr_map ifr_ifru.ifru_map /* device map */
# define ifr_slave ifr_ifru.ifru_slave /* slave device */
# define ifr_data ifr_ifru.ifru_data /* for use by interface */
# define ifr_ifindex ifr_ifru.ifru_ivalue /* interface index */
# define ifr_bandwidth ifr_ifru.ifru_ivalue /* link bandwidth */
# define ifr_qlen ifr_ifru.ifru_ivalue /* queue length */
# define ifr_newname ifr_ifru.ifru_newname /* New name */
struct ifconf {
int ifc_len; /* Size of buffer. */
union {
__caddr_t ifcu_buf;
struct ifreq *ifcu_req;
} ifc_ifcu;
};
# define ifc_buf ifc_ifcu.ifcu_buf /* Buffer address. */
# define ifc_req ifc_ifcu.ifcu_req /* Array of structures. */
以下为ioctl在设置或获取套接字属性时的一些标识
int ioctl(int fd, int request, ... /* void *arg */);
/* Socket configuration controls. */
#define SIOCGIFNAME 0x8910 /* get iface name */
#define SIOCSIFLINK 0x8911 /* set iface channel */
#define SIOCGIFCONF 0x8912 /* get iface list */
#define SIOCGIFFLAGS 0x8913 /* get flags */
#define SIOCSIFFLAGS 0x8914 /* set flags */
#define SIOCGIFADDR 0x8915 /* get PA address */
#define SIOCSIFADDR 0x8916 /* set PA address */
#define SIOCGIFDSTADDR 0x8917 /* get remote PA address */
#define SIOCSIFDSTADDR 0x8918 /* set remote PA address */
#define SIOCGIFBRDADDR 0x8919 /* get broadcast PA address */
#define SIOCSIFBRDADDR 0x891a /* set broadcast PA address */
#define SIOCGIFNETMASK 0x891b /* get network PA mask */
#define SIOCSIFNETMASK 0x891c /* set network PA mask */
#define SIOCGIFMETRIC 0x891d /* get metric */
#define SIOCSIFMETRIC 0x891e /* set metric */
#define SIOCGIFMEM 0x891f /* get memory address (BSD) */
#define SIOCSIFMEM 0x8920 /* set memory address (BSD) */
#define SIOCGIFMTU 0x8921 /* get MTU size */
#define SIOCSIFMTU 0x8922 /* set MTU size */
#define SIOCSIFNAME 0x8923 /* set interface name */
#define SIOCSIFHWADDR 0x8924 /* set hardware address */
#define SIOCGIFENCAP 0x8925 /* get/set encapsulations */
#define SIOCSIFENCAP 0x8926
#define SIOCGIFHWADDR 0x8927 /* Get hardware address */
#define SIOCGIFSLAVE 0x8929 /* Driver slaving support */
#define SIOCSIFSLAVE 0x8930
#define SIOCADDMULTI 0x8931 /* Multicast address lists */
#define SIOCDELMULTI 0x8932
#define SIOCGIFINDEX 0x8933 /* name -> if_index mapping */
#define SIOGIFINDEX SIOCGIFINDEX /* misprint compatibility :-) */
#define SIOCSIFPFLAGS 0x8934 /* set/get extended flags set */
#define SIOCGIFPFLAGS 0x8935
#define SIOCDIFADDR 0x8936 /* delete PA address */
#define SIOCSIFHWBROADCAST 0x8937 /* set hardware broadcast addr */
#define SIOCGIFCOUNT 0x8938 /* get number of devices */
#define SIOCGIFBR 0x8940 /* Bridging support */
#define SIOCSIFBR 0x8941 /* Set bridging options */
#define SIOCGIFTXQLEN 0x8942 /* Get the tx queue length */
#define SIOCSIFTXQLEN 0x8943 /* Set the tx queue length */
获取mac地址实例
#include <sys/ioctl.h>
#include <net/if.h>
#include <unistd.h>
#include <netinet/in.h>
#include <string.h>
#include <stdio.h>
int main(int argc,char *argv[]) {
struct ifreq ifr;
struct ifconf ifc;
char buf[2048];
//生成一个可用套接字描述符
int sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
if (sock == -1) {
printf("socket error
");
return -1;
}
//获取所有网络接口列表
ifc.ifc_len = sizeof(buf);
ifc.ifc_buf = buf;
if (ioctl(sock, SIOCGIFCONF, &ifc) == -1) {
printf("ioctl error
");
return -1;
}
//对子项进行操作输出
struct ifreq* it = ifc.ifc_req;
const struct ifreq* const end = it + (ifc.ifc_len / sizeof(struct ifreq));
char szMac[64];
int count = 0;
for (; it != end; ++it) {
strcpy(ifr.ifr_name, it->ifr_name);
if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
if (! (ifr.ifr_flags & IFF_LOOPBACK)) { // don't count loopback
if (ioctl(sock, SIOCGIFHWADDR, &ifr) == 0) {
count ++ ;
unsigned char * ptr ;
ptr = (unsigned char *)&ifr.ifr_ifru.ifru_hwaddr.sa_data[0];
snprintf(szMac,64,"%02X:%02X:%02X:%02X:%02X:%02X",*ptr,*(ptr+1),*(ptr+2),*(ptr+3),*(ptr+4),*(ptr+5));
printf("%d,Interface name : %s , Mac address : %s
",count,ifr.ifr_name,szMac);
}
}
}else{
printf("get mac info error
");
return -1;
}
}
return 0;
}